Switching device



Oct. 25, 1966 D. A. CORLE'Y SWITCHING DEVICE 2 Sheets-Sheet 2 Filed Feb. 20, 1964 6 mm B L R 0H TL R W0 W & v: E W E D mm ATTORNEYS United States Patent M 3,281,542 SWITCHING DEVICE Dewey A. Corley, Forest Park, Ga., assignor to Impulse!- ler, Inc., Atlanta, Ga., a corporation of Georgia Filed Feb. 20, 1964, Ser. No. 346,352 4 Claims. (Cl. 179100.1)

This invention relates to a switching system and, more particularly, to a device for switching from one sound source to another sound source in response to the absence of sound from one of the sources.

This invention is particularly suitable for use as a program alternator to switch from a first sound-reproducing source to a second sound-reproducing source at the end of a recorded message from the first source. As an eX- ample, the invention may be employed as a switching device for a commercial broadcasting station where it is desired to alternate recorded advertisements with recorded music. A first disc record player or tape deck would be supplied with a series of recorded commercial messages, such as advertisements, and a second disc record player or tape deck would be provided with a series of musical selections. At the end of each musical selection, the device according to this invention would de-energize the music source and simultaneously energize the commercial message source and, conversely, would de-energize the commercial message source and energize the music source at the end of the commercial message.

Heretofore, switching devices have been proposed to switch from one sound source to another sound source to thereby alternate the recorded selections or to switch from one sound source to another sound source when the first sound source has played all of its selections. These devices, however, are operated mechanically, for example, in response to the position of a sound pick-up tone arm or the action of a timing switch. If the sound-reproducing device was a disc record player, a switch would operate in response to a predetermined increment of travel by the tone arm to deactivate that sound source and simultaneously activate the other sound source. In a similar manner, a timing switch would deactivate one sound source and activate the other sound source after a predetermined time interval. In those devices, the length of recorded music or message, necessarily and undesirably, had to be timed for the particular time interval of the timing switch or the increments traversed by the tone arm of the record player.

Accordingly, it is an object of the present invention to overcome many of the deficiencies of the prior art switching devices.

It is a more particular object of the present invention to provide a switching device that will switch alternately from one sound source to another sound source in response to the absence of sound from one of the sources and to provide such a system with a common audio power amplifier and speaker system.

These and other objects will become apparent from the following detailed description of the present invention and from the accompanying drawings.

In the drawings:

FIGURE 1 is a schematic illustration of the switching device according to this invention.

FIGURE 2 is a more detailed invention shown in FIGURE 1.

Referring now to the drawings, two sound-reproducing devices and 11 are schematically illustrated. The devices 10 and 11 may be conventional disc record players or may be conventional tape decks. For illustrative purposes, the following discussion will be directed to a systerm in which the devices 10 and 11 are conventional disc type record players. Also for illustrative purposes, it

circuit diagram of the 3,281,542 Patented Oct. 25, 1966 will be assumed that the device 10 is supplied with disc type records having a series of musical selections recorded thereon, and the device 11 is provided with disc type records having a series of commercial announcements recorded thereon.

The circuitry shown in FIGURES 1 and 2 is illustrated with the program alternator in an On condition, and with the device 10 plugged into an outlet 10a which is connected to a -volt AC. power source 12 through a movable contact 13 and a stationary contact 14, which are associated with a coil 15. A connection 16 from the sound pick-up head of the device 10 plugs into an audio input socket 17. The socket 17 and, therefore, the connection 16 are, in turn, connected to a three-stage amplifier 18 through a movable contact 19 and a stationary contact 20.

The amplifier 18 receives DC. voltage from the AC. source 12 through a rectifier network 21. The audio signal from the sound pick-up head of the device 10 is amplified by transistors 22 and 23. This amplified signal is taken off a volume control resistor 24, further amplified by a transistor 25, and delivered to an audio power amplifier 26 through an audio output socket 27. The amplifier 26 is a conventional power amplifier which may be employed to drive suitable speakers (not shown). The audio signal from the device 10 is also supplied from the first two stages of the amplifier to a two-stage amplifier 28 by a connection 29. The signal is amplified by transistors 30 and 31, and is applied to the base of a transistor 32 through a transformer 33. As long as this signal appears at the base of the transistor 32, there is a low collector-to-emitter resistance of the transistor. This low resistance in the transistor 32 permits current to flow from the rectifier network 21 and energize a coil 34 of a relay 35. Thus, as long as a signal is present at the base of the transistor 32, the coil 34 will be energized, and a normally closed switch 36 will be held open.

When the signal is no longer received from the device 10, i.e., when the stylus is at a silent portion of the sound track between musical selections, there is a high collectorto-emitter resistance in the transistor 32 and the relay coil 34 is de-energized. When the coil 34 is de-energized, the normally closed switch 36 will close and complete a circuit to energize a coil 37. When the coil 37 is energized, a sliding contact 38 of a step switch 39 will move from a stationary contact 40 to a stationary contact 41.

The step switch 39 is a conventional device and includes the sliding contact 38, the coil 37, and contacts 40, 41, and 42. The step switch 39 further includes an outer wire 43, an inner wire 44, and an inner contact ring 45. The inner contact ring is connected to the AC. source 12 by a lead wire 46, and the outer wire 43 is connected to the AC. source by a lead wire 47 through the coil 15.

In a manner that will hereinafter become apparent, the coil 37 is energized for a brief time interval. During this brief interval, the sliding contact 38 moves one step in the illustrated contact series comprising the steps 40-41, 41-40, 40-42, 42-40, etc.

' When the sliding contact 38 is moved one step from the open contact 40 to the contact 41, a circuit is completed from the lead wire 46 to the lead wire 47 through the inner contact ring 45, the contacts 38 and 41, the inner Wire 44, a manually operated closed switch 48, the outer Wire 43, a manually operated closed switch 49, and the coil 15. The completion of this circuit energizes the coil 15 and opens the contacts 13 and 14 and the contacts 19 and 20, and closes a movable contact 50 against a stationary contact 51 and, also, a movable contact 52 against a stationary contact 53. When the contacts 13 and 14 are opened, the power to the outlet 10a: is cut off, and when the contacts 52 and 53 are closed, the outlet the contacts 50 and 51 connects an audio input socket 54 to the three-stage amplifier 18. A connection 55 from the sound pick-up head of the device 11 plugs into the audio input socket 54.

With the coil 15 energized, therefore, the device and its sound pick-up head output are disconnected from the AC. source 12', and the device 11 and its sound pickup head output are connected to the AC. source 12. As was previously indicated, the device 11 may be provided with a series of commercial messages which are recorded on disc type records. The coil 15 will remain energized until the commercial message is completed, since the absence of a signal at the base of the transistor 32 will tie-energize the coil 34, close the switch 36, momentarily energize the coil 37, move the sliding contact 38 to an open contact 40, and thereby de-energize the coil 15 to return the contacts 13, 14, 19, and to the positions illustrated in FIGURES l and 2 of the drawings.

As was indicated above, the coil 37 is momentarily energized when the switch 36 is closed. The closure of the switch 36 energizes the coil 37 through a pair of normally closed contacts 56 and 57. When the coil 37 is energized, it closes normally open contacts 58 and 59 to energize a coil 60. When the coil 6t? is energized, normally open contacts 61 and 62 are closed, and normally closed contacts 56 and 57 are opened to de-energize the coil 3'7. Although the coil 64) remains energized until the switch 36 is opened, the coil 37 is energized for an instant to move the sliding contact 38 one position.

To prevent premature switching between the devices 10 and 11 during musical or voice pauses, a delay mechanism 70 is provided between the transistor 32 and the coil 34. The delay mechanism 70 comprises a capacitor 71 and a variable resistor 72. The operation of the coil 34 depends on the rate of discharge of the capacitor 71 and this rate is in turn dependent upon the adjustment of the variable resistor 72. Since each musical selection is separated from an adjacent musical selection by a silent portion of the sound track, which lasts from between 10 and 20 seconds, and since the adjacent commercial messages are separated by a similar silent portion of the sound track, the capacitor 71 may be tuned to discharge after a time period that is slightly less than the time it takes the stylus to traverse the silent portion of the sound track.

With the manually operated switch 48 in a closed position, the devices 10 and 11 will be alternately activated to alternate musical and commercial selections. If the switch 48 is opened, however, the device it) will play three selections to one selection from the device 11. With the switch 48 opened, the contacts 41 become open contacts similar to the contacts 40, and a circuit'is completed between the leads 46 and 47 only when the sliding contact 38 is on a contact 42. The device 10, therefore, remains activated as the sliding contact 38 successively engages the contacts 40, 41, and 40, and the device 11 is activated when the. sliding contact 38 is stepped into engagement with the contact 42.

The program alternator may be operated on a semiautomatic basis by opening the switch 49. When the switch 49 is opened, the device 10 will operate on a continuous basis, since the coil 15 cannot be energized. If the station operator feels that a commercial message should be played, he may close the switch 49, and, at the end of the musical selection then playing, the coil 15 will be energized to operate the device 11 (assuming that the switch 48 is closed or, it opened, assuming that contact is made between the ring 45 and a contact 42).

The program alternator is operated by connecting the receptacle plugs of the audio power amplifier 26, the device 10, and the device 11 to their respective outlets 26a, 10a, and 11a. The input to the audio power amplifier 26 is plugged into the socket 27, and the connections 16 and 55 are plugged into the sockets 17 and 54,

respectively. A switch comprising the elements and 81 is operated so that the element 80 is closed and the element 81 is open, as is indicated in FIGURE 2. The manually operated switches (not shown) of the devices 10 and 1.1 are then turned on, with each stylus positioned in a silent portion of its sound track.

As soon as the switch comprising the elements 80 and 81 is operated, the coil 6% is energized and, therefore, the coil 37 is momentarily energized to move the sliding contact 38 one position. The coil 60 will remain energized until the stylus that is in operation reaches the sound portion of its track and supplies a signal to the base of the transistor 32 to energize the coil 34 and open the switch 36.

Many modifications and variations of the preferred embodiment of the invention will be apparent to those skilled in the art in light of the above disclosure. Therefore, it is to be understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically shown and described herein.

What is claimed is:

1. A switching device for alternately connecting the sound output of a plurality of sound-reproducing means to a power amplifier in response to the discontinuance of a signal from one of the sound-reproducing means, comprising a plurality of sound-reproducing means, and means for maintaining a connection between the sound output of one of said sound-reproducing means and a power amplifier while said one sound-reproducing means is transmitting a signal, said connection maintaining means including means for amplifying the sound output of each of said sound-reproducing means, first and second coil means, a multiple contact step switch having contact means for alternately energizing and dc-energizing said second coil means, said first coil means being energized in response to the amplified sound output of each of said sound-reproducing means, and being =de-energized in re sponse to the discontinuance of said sound output, the contacts of said step switch being operated in response to said first coil means, means responsive to the energizing and tie-energizing of said second coil means for alternately and respectively connecting and disconnecting the sound output of a first one of said sound-reproducing means to and from a power amplifier and for substantially simultaneously disconnecting and connecting the sound output of a second one of said sound-reproducing means from and to said power amplifier.

2. A switching device for alternately connecting the sound outputs of a plurality of sound-reproducing means to a power amplifier and for connecting the power inputs of said sound-reproducing means to a power source in response to the discontinuance of a signal from one of the sound-reproducing means, comprising a plurality of sound-reproducing means, and means for maintaining a connection between the sound output of one of said sound-reproducing means and a power amplifier and for maintaining a connection between the power input of said one sound-reproducing 1111821118 and a power source while said one sound-reproducing means is transmitting a signal, said connection maintaining means including means for amplifying the sound output of each of said sound-reproducing means, first and second coil means, a multiple contact step switch having contact means for alternately energizing and dfl-finfilgiZiIlg said second coil means, said first coil means being energized in response to the amplified sound output of each of said sound-reproducing means and being tie-energized in response to the discontinuance of said sound output, the contacts of said step switch being operated in response to said first coil means, means responsive to the energizing and de-energizing of said second coil means for alternately and respectively connecting and disconnecting the sound output of a first one of said sound-reproducing means to and from a power amplifier and for substantially simultaneously disconnecting and connecting the sound output of a second one of said sound-reproducing means from and to the power amplifier, and means responsive to the energizing and de-energizing of said second coil means for alternately and respectively connecting and disconnecting the power input of said first one of said sound-reproducing means to and from the power source and for substantially simultaneously disconnecting and connecting the power input of the second one of said sound-reproducing means from and to said power source.

3. A switching device for alternately connecting the sound outputs of a plurality of sound-reproducing means to a power amplifier in response to the discontinuance of the signal from one of the sound-reproducing means, comprising a plurality of sound-reproducing means, and means for maintaining a connection between the sound output of one of said sound-reproducing means and a power amplifier while said one sound-reproducing means is transmitting a signal, said connection maintaining means including means for amplifying the sound output of each of said sound-reproducing means, first and second coil means, means responsive to the operation of said first coil means for alternately energizing and de-energizing said second coil means, said first coil means being energized in response to the amplified sound output of each of said sound-reproducing means, and being tie-energized in response to the discontinuance of said sound output, means responsive to the energizing and de-energizing of said second coil means for alternately and respectively connecting and disconnecting the sound output of a first one of said sound-reproducing means to and from a power amplifier and for substantially simultaneously disconnecting and connecting the sound output of a second one of said sound-reproducing means from and to said power amplifier.

4. A switching device for alternately connecting the sound outputs of a plurality of sound-reproducing means to a power amplifier in response to the discontinuance of a signal from one of the sound-reproducing means, comprising a plurality of sound-reproducing means, each of said sound-reproducing means being provided with a sound track carrying a series of sound recordings separated by silent t-rack portions, and means for maintaining a connection between the sound output of one of said sound-reproducing means and a power amplifier While said one sound-reproducing means is transmitting a signal, said connection maintaining means including means for amplifying the sound output of each of said sound-reproducing means, first and second coil means, means responsive to the operation of said first coil means for alternately energizing and de-energizing said second coil means, said first coil means being energized in response to the amplified sound output of each of said sound-reproducing means, and 'being de-energized in response to the discontinuance of said sound output, means responsive to the energizing and de-energizing of said second coil means for alternately and respectively connecting and disconnecting the sound output of a first one of said sound-reproduc ing means to and from a power amplifier and for substantially simultaneously disconnecting and connecting the sound output of a second one of said sound-reproducing means from and to said power amplifier and including means to delay the operation of said first coil means for a time period that is greater than normal sound transmission pauses but less than the time period of said silent track portions.

References Cited by the Examiner UNITED STATES PATENTS 1,852,727 4/1932 Van der Horst 179100.1 2,252,327 8/1941 Lovett et a1 179-100.11 2,946,852 7/1960 Brown et a1. 179-6 2,995,630 8/1961 Kabrick et al. 179100.1

BERNARD KONICK, Primary Examiner.

IRVING SRAGOW, Examiner.

A. F. BERNARD, Assistant Examiner. 

3. A SWITCHING DEVICE FOR ALTERNATELY CONNECTING THE SOUND OUTPUTS OF A PLURALITY OF SOUND-REPRODUCING MEANS TO A POWER AMPLIFIER IN RESPONSE TO THE DISCONTINUANCE OF THE SIGNAL FROM ONE OF THE SOUND-REPRODUCING MEANS, COMPRISING A PLURALITY OF SOUND-REPRODUCING MEANS, AND MEANS FOR MAINTAINING A CONNECTION BETWEEN THE SOUND OUTPUT OF ONE OF SAID SOUND-REPRODUCING MEANS AND A POWER AMPLIFIER WHILE SAID ONE SOUND-REPRODUCING MEANS IS TRANSMITTING A SIGNAL, SAID CONNECTION MAINTAINING MEANS INCLUDING MEANS FOR AMPLIFYING THE SOUND OUTPUT OF EACH OF SAID SOUND-REPRODUCING MEANS, FIRST AND SECOND COIL MEANS, MEANS RESPONSIVE TO THE OPERATION OF SAID FIRST COIL MEANS FOR ALTERNATELY ENERGIZING AND DE-ENERGIZING SAID SECOND COIL MEANS, SAID FIRST COIL MEANS BEING ENERGIZED IN RESPONSE TO THE AMPLIFIED SOUND OUTPUT OF EACH OF SAID SOUND-REPRODUCING MEANS, AND BEING DE-ENERGIZED IN RESPONSE TO THE DISCONTINUANCE OF SAID SOUND OUTPUT, MEANS RESPONSIVE TO THE ENERGIZING AND DE-ENERGIZING OF SAID 